This application claims benefit of Japanese Patent Application No. 2000-257347 filed on Aug. 28, 2000, the contents of which are incorporated by the reference. The present invention relates to a lead frame set and, more particularly, to elastic surface wave (SAW) filters used for portable telephone sets and the like and also lead frames used in such SAW filters.
Prior art SAW filters are disclosed as, for instance, xe2x80x9cElastic Surface Wave Devicesxe2x80x9d in Japanese Patent Laid-Open No. 5-63495. Also, prior art leads frames for such electronic components as IC (semiconductor integrated circuit) are disclosed, for instance, as xe2x80x9cTAB Tapexe2x80x9d in Japanese Patent Laid-Open No. 5-121492 and as xe2x80x9cSemiconductor Device and Method of Manufacturing the Samexe2x80x9d in Japanese Patent Laid-Open No. 10-270626.
FIG. 11 is a plan view showing an example of such prior art lead frames. FIG. 12 is a plan view showing an SAW filter using these lead frames. The lead frames are shown together with a resin molding 5 for securing them thereto. Each lead frame has an inner and an outer lead 1 and 2. The lead frames each having the inner and outer leads 1 and 2 are coupled together at a predetermined interval by a tie bar (or carrier) 3. In the prior art lead frame set as shown, the pitches or intervals A1 and A2 of the inner and outer leads 1 and 2 were the same (i.e., A1=A2), and also the widths A3 and A4 of the inner and outer leads A3 and A4 were the same (i.e., A3=A4).
With the same pitches A1 and A2 of the inner and outer leads 1 and 2 and also with the same widths A3 and A4 thereof, however, restrictions are imposed on the design of the inner and outer leads 1 and 2 of the SAW filter. These restrictions lead to a problem of reducing the scope of the leads (matching) with respect to PWB (i.e., printed wiring board) for connector (which the leads are mounted in.
An object of the present invention is to solve the above problem inherent in the prior art by the provision of lead frames, which is used for small-in-size, light-in-weight and highly integrated portable telephone terminals or the like and has high versatility of connection to the PWB, and also an SAW filter using such lead frames.
According to an aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: at least the widths or the pitches of the inner and outer leads are chosen to be different values.
According to another aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: at least the widths or the pitches of the inner and outer leads are chosen to be different values and the lead frames each have a transient portion intervening between the inner and outer leads and have the transient portion secured to a resin molding base.
The inner and outer leads are matched in position to the top and bottom surfaces, respectively, of a bottom portion of the resin molding base.
According to other aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be greater than that of the inner leads and the width of the outer leads is chosen to be greater than that of the inner leads.
According to further aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be less than that of the inner leads and the width of the outer leads is chosen to be the same as that of the inner leads.
According to still further aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be greater than that of the inner leads and the width of the outer leads is chosen to be less than the width of the inner leads.
According to other aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be less than that of the inner leads and also the width of the outer leads is chosen to be less than that of the inner leads.
According to still other aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be greater than that of the inner leads and the width of the outer leads is chosen to be less than that of the inner leads.
According to other aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be the same than that of the inner leads and the width of the outer leads is chosen to be less than that of the inner leads.
According to still aspect of the present invention, there is provided a lead frame set comprising a plurality of lead frames disposed in parallel and each having an inner lead and an outer lead, wherein: the pitch of the outer leads is chosen to be the same than that of the inner leads and the width of the outer leads is chosen to be greater than that of the inner leads.
According to further aspect of the present invention, there is provided an SAW filter comprising the lead frame set according to one of claims 1 and 4-10, and an SAW chip connected to the inner leads of the lead frames.
The lead frames each have a transient portion intervening between the inner and outer leads, the transient portion being secured to a resin molding base. The lead frames each have a transient portion intervening between the inner and outer leads, the transient portion being secured to a resin molding base, the bottom surface of the outer leads of the lead frames are made to be substantially flush with the bottom surface of the resin molding base, and the width and the pitch of the outer leads are matched to the wiring pattern of a connector board. The lead frames each have a transient portion intervening between the inner and outer leads, the transient portion being secured to a resin molding base and the SAW chip and a connector part are covered by a resin molding cap.
Other objects and features will be clarified from the following description with reference to attached drawings.